A baby at week 23 of development is more than halfway through the second trimester, which lasts from week 14 to week 28. During the second trimester, your baby's organs are starting to develop enough to become functional. Although every baby...
Since the early 1960s, the number of asthma cases have exploded, according to a November 2007 study published in the "Journal of Allergy and Clinical Immunology." During the same period, cases of vitamin D deficiency also skyrocketed. Could the...
Phencyclidine, or PCP, is often categorized as a hallucinogen but is properly known as a dissociative drug, according to the National Institute on Drug Abuse. The mind-altering effects of PCP include distorted perceptions of the senses and a...
Lung development in a fetus starts during the embryonic phase, at around four weeks of gestational age. Very early in development, what will eventually be a baby is nothing more than a cell ball, where none of the cells are yet specialized. An...
From the time sperm meets egg until the moment a fully formed baby human is delivered into the world, a fantastically complicated series of events unfolds. In addition to the first single cell of a new life--the fertilized egg--having to divide...
The term hernia refers to the protrusion of an organ through an opening in the wall that normally contains it. In a diaphragmatic hernia, a defect in the wall of the diaphragm allows organs from the abdomen to push through. According to the book...
Babies do not actually breathe in the womb---at least, not in the usual sense. Fetal lungs are not fully functional, and are not even able to fully expand, until after birth. During the later stages of gestation, the fetus may "practice" breathing...
A human fetus develops over the course of about 38 weeks of pregnancy. This developmental process follows a precisely ordered and timed set of stages. Scientists have characterized these stages in enough detail to fill several books. Several...
A baby needs a fully developed set of lungs in order to breathe well on her own and to provide enough oxygen for her body's tissues. A premature baby's lungs may be underdeveloped, causing difficulty with breathing and putting the baby at risk of...
According to the National Institute of Child Health and Human Development, about 12 percent of all births in the United States are premature, taking place before the 37th week of gestation. Premature birth can lead to numerous complications. The...
Artichokes may look inedible, but the tender heart makes a tasty option for your diet. Marinating artichokes adds a rich dimension of flavor -- the marinade generally contains olive oil and other seasonings. These artichokes are suitable for...
The lungs are the organs responsible for gas exchange. Humans require oxygen for cellular respiration, and they produce carbon dioxide as a waste product. The lungs are composed of a number of multiple levels of branching airways, called bronchi....
The human fetus develops according to a set of precisely ordered and timed stages. The mother's egg is fertilized by the father's sperm and becomes a zygote---a single cell containing a new, complete set of DNA. This zygote rapidly divides and...
A marginal placenta previa describes a placenta that lies within 2cm of the cervical os but does not overlie the os. Treatment depends on whether or not the woman has bleeding, how far along she is in her pregnancy and whether the previa persists...
A fetus develops according to a precisely ordered and timed set of stages during a pregnancy, which on average lasts between 38 to 42 weeks. When the mother's egg is fertilized---usually in one of the mother's fallopian tubes---by the father's...
Patent Foramen Ovale (known as PFO) is a remnant of embryologic development. A small flap located between the upper heart chambers allows the passage of the mother's oxygen-rich blood via the umbilical cord to the developing fetus. Since the lungs...
Human development in the womb is a complex process. Lasting 40 weeks on average, it can actually be completed in anywhere from 38 to 42 weeks. In this relatively short time, a single fertilized egg grows and develops into a complete human baby....
Vitamin A is a necessary nutrient during pregnancy that contributes to your health and the development of the fetus; however, like many vitamins, it can be dangerous to consume too much of it. It is important to know how much vitamin A you need...
The earliest stage of fetal development is the fertilization of an egg cell with a sperm, causing the formation of a zygote. The zygote is a small one-celled entity that then begins to divide into a cluster of cells called a blastocyst. As it...
Before the fetus is born, a precisely ordered and timed set of developments takes place. Over the course of eight weeks, a single, fertilized egg cell grows into a ball of cells called the blastocyst, then an embryo and then a fetus. The fetus...
Your body needs a steady supply of vitamins to grow, develop properly and stay healthy. The body especially needs 13 essential vitamins, each performing a different function. To ensure that the amounts of vitamins in your body remain adequate and...
A woman in her first trimester of pregnancy may not yet show it on the outside, but her developing fetus is undergoing myriad changes on the inside during this early stage of gestation. If you were able to peek inside the world of a 6-week-old...
When the mother's egg is fertilized by sperm, it forms a single cell called a zygote. The zygote grows into a ball of cells called a blastocyst and embeds itself into the wall of the mother's uterus. Over the subsequent two weeks, it becomes an...
A fetus develops over the course of a 38- to 42-week pregnancy, from a single, fertilized egg cell---called a zygote---into a full-term fetus, ready for life outside the womb. After being fertilized, the zygote divides and replicates itself...
Over the course of a normal pregnancy, a single fertilized egg cell develops into a full-term fetus. The process usually lasts between 38 and 42 weeks and consists of a large number of stages that occur in a particular order at specific times....
The human fetus develops in the mother's womb over the course of approximately 38 weeks. The development is remarkably complex and follows a precisely-timed set of steps. The growth stages have been characterized in great detail, but several of...
A normal pregnancy lasts 38 to 42 weeks, during which a single, fertilized egg grows into a full-term fetus, ready for life outside the womb. The growth that takes place before birth progresses through a set of precisely timed and ordered stages...
At 12 weeks, the embryo is a fetus. According to the Endowment for Human Development, "a second huge burst of growth" has occurred between 11 and 12 weeks and increased its weight "by roughly 58 percent." The fetus is about 2-1/2 inches in length...
According to the National Institutes of Health (NIH), an embryo becomes a fetus in its ninth week of development. Between its ninth and 20th weeks, it has long, thin limbs and a well-defined face. Its genitals are defined, and the first buds...
